Math 2 1 By: Claudia Subtracting integers: 2 – (-8) Rule When we subtract we ADD THE OPPISITE! (never change the first number!) 2 + 8 is the same as 2 – (-8)….. So, the answer is the same, 10 -8 + 2 = -6 The answer is positive because you always use the sign of the number with the highest absolute value. -8 is farther away from zero then 2 is. So 8 has the highest absolute value. Vocab: Integers – the set of whole numbers and their opposites. Absolute Value – the distance the number is from zero on the number line. 2 How to Multiply Integers When multiplying integers with the same sign the product is always positive. When multiplying integers with different signs the answer will always be negative. If any of the integers is zero the result is always zero. 3 Adding Integers Subtracting Integers Ex: 5+3=8 Add the numbers as if they were positive, then Ex: -5-(-3) add the sign of the numbers. =-5+3 When we subtract, wesign= ADD THE 1. Adding Integers having the same OPPOSITE -5+(-3)= -8 Ex: 2-1two then turns into 2+(-1) It helps us to get the right 2.Rule: Adding integers having signs: answer, too, and less confusing. Ex: -5+3 Take the difference of the numbers as if they were positive, then add the sign of the number having absolute value. Ex: -5+3=-2 4 Dividing Integers Multiplying Integers If a pair of integers has the same sign, then the answer will have a positive sign. You must calculate the absolute value of each integer and then divide the first integer by the second integer. Step 1: |-10| / |-2| = 10 / 2 Step 2: 10 / 2 = 5 Step 3: Since integers have same sign, answer is positive: +5 When having two integers with different signs, the product is always negative Example 1: -2 · 5 = (-2)+(-2)+(-2)+(-2)+(-2) = -10 Example 2: 2 · (-5) = (-5)+(-5) = -10 When multiplying more than two integers Example 1: (-1) · (-2) · (-3) = ? Example: -10 / +2 = ? Step 1: |-10| / |+2| = 10 / 2 Step 2: 10 / 2 = 5 Step 3: Since integers have different signs, negative: -5 If a pair of integers have different signs, then the answer will be negative. You must calculate the absolute value of each integer and then divide the first integer by the second integer. Example 1: -2 · (-5) = 10 Example 2: 2 · 5 = 10 When multiplying two integers having the same sign, the product is always positive Example: -10 / -2 = ? answer is Step 1: group the first two numbers and use rules I and II above to calculate the intermediate step (-1) · (-2) = +2 (used rule I) Step 2: use result from intermediate step 1 and multiply by the third number. 2 · (-3) = -6 (used rule II) 5 6 Subtracting Integers • Convert the problem to addition. Ex. 12-(-36) to 12+36. remember to change the last number of the sequence from negative to positive or positive negative. • Add or subtract the problem like a regular math problem. Ex. 12+36=48. • Ex 126-(-176) 126+176=302 or 126-176 126+(-176)=(-50) or -126-(-176) -126+176=50 (note) when you add integers remember that when you add integers with the same sign the answer is going to be the same as the sign, but if the absolute value of the negative number is higher than the positive than the numbers going to be a negative. 7 When the number in the equation is negative positive you thenadd the opposite you convert the to the number number. to aThen positive. you Then add the you oppositethe change to operation the answer. to That its opposite. way, theAfter variable that,isyou alonethe add onopposite the left side to the of number. the equation Theninyou thisadd example, the and the difference opposite to the answer. of theThat answer way,and thethe variable opposite is number alone onisthe onone the side other. of the equal sign, and the difference of the answer and the opposite number is on the other. Example X-(-13)=13 X+13=26 X+13+(-13)=26+(-13) X+13+(-13)=26+(-13) 26+(-13)=13 26+(-13)=13 13+(-13)=0 13+(-13)=0 X=13 X=13 13-(-13)=26 13+13=26 8 9 Distributive Property For Algebra Take both numbers in the parentheses and multiply them separately to the number outside of the parentheses, still using the sign in between both numbers in parentheses. Ex. 1 : turns into Ex. 2 : 5(-Y+9) turns into 5(-Y)+59 = 5(- Y)+45 Ex. 3: -5(Y-9) turns into -5Y-(-59) = -5Y - (-45) How to Solve Equations Step 1 Created Step 2 By: Step 3 Jonah A legal move (you have to do the same thing to both sides) is very simple. What you are trying to do here is; you want to get the variable alone. All you have to Once thethe constant is gone, add the same number you added to the sum, do is add opposite to theyou constant then whatever you get from that equation, is what the variable equals Example: X + 5 = 12 Example: X + 5 + (-5) = 12 + (-5) X + 5 + (-5) = 12 + (-5) X = 7 10 By: Cameron When subtracting integers you “add the opposite”. Example: 12-8=4 12+(-8)=4 Rule When Subtracting Integers you add the opposite. Example: 10-(-4)=14 10+4=14 Do you want to know how this works~ click to find 11 out. Just draw a number line if it helps you more. Also when you have a subtraction sign next to a parenthesis. You change the sign to addition and the negative number to a positive. Example: -10-(-4)=14 10+4=14 Example2: -10-(4)=6 -10+-4=14 12 HOW TO COMBINE LIKE TERMS Congrats you can nowALGEBRAIC simplify algebraic A.K.A. SIMPLIFYING EXPRESSIONS expressions!!!!!!!! Terms --- The Step 13 Hint The only like terms are 3x & 2x begin with an You Begin simplifying simplify Step 2 Before Algebraic Expression to 3x+y+2x+7=? 3x+2x=5x Final answer and find………………….. 5x+y+7 The Surprise Expression we simplify, find the terms, like terms, coefficients, and constants. algebraic expression separated between each plus or minus sign Ex. 3x, y, 2x, 7 Like terms --- Terms that conduct the same variables Ex. 3x & 2x Coefficients --- The numbers that are involved with a variable Ex. 3, 2, 1 Constants --- Terms without an variable Ex. 7 By Lennon Dresnin You solve an algebraic equation by doing different sets of legal moves. You do a legal move by adding or subtracting and in some cases multiplication and dividing what you do to one side to the other until you cant do anymore moves. example: 3+4+-4=Y+4+-4+3